Pneumatic conveying systems refer to the systems for transportation of pulverized solid particles carried by a fluid gas forming a solid-gas mixture from one vessel to another vessel through a pipeline or multiple pipelines. The pneumatic conveying systems have been widely used in various industrial fields such as IGCC (Integrated Gasification Combined Cycle) plants for generating electricity and chemical plants for producing chemicals.
In the pneumatic conveying systems, it is typically necessary to measure the real time solid mass flow rate (shortened as “solid flow rate” hereinafter) for controlling and monitoring purpose. The real time solid flow rate is generally defined as the quantity of mass of solid particles that flow through the cross sectional area of a conveying pipeline of the pneumatic conveying systems per time unit. Currently, there are many ways for determining the real time solid flow rate. One conventional process uses a solid flow rate sensor to directly measure and output the real time solid flow rate. Another process uses multiple sensors that together determine the real time solid flow rate. Some of the multiples sensors are firstly used to determine a mixture flow rate of the solid-gas mixture, and the others are used to determine a gas flow rate. The real time solid flow rate is obtained by subtracting the gas flow rate from the mixture flow rate.
However, during both of these conventional ways for determining the real time solid flow rate, only one measured value of the real time solid flow rate is obtained. As a result, it is very difficult to achieve a reliable real time solid flow rate if any of the sensors is broken or not working properly. Therefore, there is a need to provide improved systems and methods for a reliable real time solid flow rate measurement.